Refractive index changes in LiNbO3 caused by compensations of lithium ions

Abstract

Changes of LiNbO3 composition induce refractive index changes. Refractive index changes in LiNbO3 fabricated by vapor transport equilibration process was investigated using the Z-scan method and Maker's fringe experiment. In non-critical phase matched second-harmonic generation, the phase matching temperature and the birefringence change for temperature were measured. The phase matching temperature of Li-compensated LiNbO3 was observed around 230 degrees C and the birefringence change for temperature was smaller than that of congruent LiNbO3.